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SiC particle reinforced metal matrix composites (MMCs) with solid semi stir casting method is becoming popular in recent application (automotive, aerospace). Stirring the semi solid condition is proven to enhance the bond between matrix and reinforcement. The purpose of this study is to investigate the effect of the SiC wt.% and the addition of borax on mechanical properties of composite AlSi-Mg-TiB-SiC and AlSi-Mg-TiB-SiC/Borax. Specimens was tested focusing on the density, porosity, tensile test, impact test microstructure and SEM. AlSi is used as a matrix reinforced by SiC with percentage variations (10, 15, 20 wt.%). Giving wt.% Borax which is the ratio of 1: 4 between wt.% SiC. The addition of 1.5% of TiB gives grain refinement. The use of semi-solid stir casting method is able to increase the absorption of SiC particles into a matrix AlSi evenly. The improved composite presented here can be used as a guideline to make a new composite. [ABSTRACT FROM AUTHOR]

One way to extend the life time of the gear is minimizing the distortion during the manufacturing process. One of the most important processes in manufacturing to produce gears is heat treatment process. The purpose of this study is to analyze the distortion of the gear after heat treatment process. The material of gear is AISI 1045, and it was designed with the module (m) 1.75, and a number of teeth (z) 29. Gear was heat-treated in the furnace at a temperature of 800°C, holding time of 30 minutes, and then quenched in water. Furthermore, surface hardening process was also performed on gear teeth at a temperature of 820°C and holding time of 35 seconds and the similar procedure of analysis was conducted. The hardness of gear after heat treatment average 63.2 HRC and the teeth surface hardness after gear to induction hardening was 64.9 HRC at the case depth 1 mm. The microstructure of tested gear are martensitic and pearlite. The highest distortion on tooth thickness to upper than 0.063 can cause high precision at the tooth contact is not appropriate. Besides the shrinkage of tooth thickness will also affect to contact angle because the size of gear tolerance was not standardized. [ABSTRACT FROM AUTHOR]

Magnesium matrix composites reinforced with SiCp particles were fabricated using the semi-solid stir casting process. The purpose of the study was to the effects concentration wt% SiCp and TiB of the mechanical properties of composites Al-Mg-2TiB/SiCp and Al-Mg-4TiB/SiCp. Variations (3, 6, 9 wt.%) SiCp/Al-Mg composites with different SiCp and TiB contents were successfully fabricated by semi-solid stir casting. Mechanical stirring technique carried out in conditions of semi-solid to obtain SiCp particles evenly dispersed. Effects of SiCp and TiB content on mechanical properties were studied by density, porosity, hardness test, impact test and microstructure images. The results indicate that SiCp particles disperse homogeneously in AZ81A matrix, and interfacial reaction between matrix and SiCp particles is effectively controlled. Distribution of SiCp reinforcement and interfacial bonding are improved by adding TiB. Additionally, the mechanical properties of composites are remarkably improved with the SiCp and TiB content increasing. The addition of (2 and 4 wt%) TiB gives grain refinement on the AZ81A matrix. [ABSTRACT FROM AUTHOR]

Magnesium matrix composites reinforced with SiCp particles were fabricated using the semi-solid stir casting process. The purpose of the study was to the effects concentration wt% SiCp and TiB of the mechanical properties of composites Al-Mg-2TiB/SiCp and Al-Mg-4TiB/SiCp. Variations (3, 6, 9 wt.%) SiCp/Al-Mg composites with different SiCp and TiB contents were successfully fabricated by semi-solid stir casting. Mechanical stirring technique carried out in conditions of semi-solid to obtain SiCp particles evenly dispersed. Effects of SiCp and TiB content on mechanical properties were studied by density, porosity, hardness test, impact test and microstructure images. The results indicate that SiCp particles disperse homogeneously in AZ81A matrix, and interfacial reaction between matrix and SiCp particles is effectively controlled. Distribution of SiCp reinforcement and interfacial bonding are improved by adding TiB. Additionally, the mechanical properties of composites are remarkably improved with the SiCp and TiB content increasing. The addition of (2 and 4 wt%) TiB gives grain refinement on the AZ81A matrix. [ABSTRACT FROM AUTHOR]

One way to extend the life time of the gear is minimizing the distortion during the manufacturing process. One of the most important processes in manufacturing to produce gears is heat treatment process. The purpose of this study is to analyze the distortion of the gear after heat treatment process. The material of gear is AISI 1045, and it was designed with the module (m) 1.75, and a number of teeth (z) 29. Gear was heat-treated in the furnace at a temperature of 800°C, holding time of 30 minutes, and then quenched in water. Furthermore, surface hardening process was also performed on gear teeth at a temperature of 820°C and holding time of 35 seconds and the similar procedure of analysis was conducted. The hardness of gear after heat treatment average 63.2 HRC and the teeth surface hardness after gear to induction hardening was 64.9 HRC at the case depth 1 mm. The microstructure of tested gear are martensitic and pearlite. The highest distortion on tooth thickness to upper than 0.063 can cause high precision at the tooth contact is not appropriate. Besides the shrinkage of tooth thickness will also affect to contact angle because the size of gear tolerance was not standardized. [ABSTRACT FROM AUTHOR]